<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<button>发送</button>
<script>
    var btn = document.querySelector('button');
    var time = 5;
    btn.addEventListener('click',function () {
            btn.disabled = true;
            var times = setInterval(function () {
                if (time == 0) {
                    clearInterval(time);
                    btn.disabled = false;
                    btn.innerHTML = '发送';
                    time = 5;
                }else {
                    btn.innerHTML = '下次点击还剩下'+time+'秒';
                    time--;
                }
            },1000);
    })
</script>
</body>
</html>